Can't import .mxf files

Hi...

I downloaded the trial version of Encoder to convert some .mxf files to see how quick Encoder did it before we decided to purchase another license (we have one on another machine).  For some reason when I try to import any .mxf file, it is giving me an error saying the file must be corrupt.  Yet it loads on the other machine with encoder.  Is it because I am running a trial version?  I have episode and can convert .mxf files all day but we need to make files with multiple burn-ins which Episode can't do.

Any ideas?

Thanks!